A variety of container types for packaging liquid products are currently available.
One type of container is collapsible and comprises two flexible side walls and a bottom wall, which walls are joined to each other along a connecting portion to form a compartment, whose volume is dependent on the relative position of the walls.
Before filling, this type of container can be in a flat and sealed state. As a result, it will be possible to sterilise the compartment of the container in connection with manufacture and, with maintained sterility, distribute the container to a filling plant, such as a dairy.
A container of the type described above is known from WO99/41155 which also discloses a device for filling a container.
Said device comprises a nozzle which is insertable into a filling duct of the container, which filling duct is opened by cutting or the like operation in connection with filling of the container.
During the actual filling process, said nozzle is thus inserted into the filling duct, after which a product valve is opened to supply the desired amount of product to the compartment of the container through said nozzle. The compartment will assume a volume which substantially corresponds to the volume of the supplied product. The filling process ensures that intrusion of air into the compartment is prevented or, in any case, reduced to a minimum.
The filling device disclosed in WO99/41155 comprises more specifically a nozzle which is made of an elastic material, such as silicone rubber. The nozzle has an end portion which tapers toward an outlet in the form of a gap in the lower end surface of the end portion.
The nozzle is self-closing, which means that the edge portions defining said gap engage each other in the absence of exterior forces.
During the filling process, the nozzle is, as mentioned above, inserted into the filling duct of the container, after which the product is supplied to the compartment through said nozzle. The product pressure will act to open the nozzle and at the same time to establish a seal between the nozzle and the walls of the filling duct so as to ensure that air does not enter the container.
Increasing requirements are placed on the efficiency of filling devices of the type described above and, thus, also on the speed at which the device allows filling of an individual container.
Faster filling can be provided with an increased product flow rate, which results in a higher product pressure. It has been found that an increased product pressure can in some cases result in product being pressed out of the compartment of the container between the nozzle and the walls of the filling duct. Obviously this results in difficulties in maintaining a hygienic environment in the filling device.
WO03/026969 discloses a device for filling a bag with a pulverulent or liquid material. The device comprises a boat-shaped adapter which is connected to a filling tube and a clamping means which is shaped complementarily to the adapter. For filling of the bag, the adapter is inserted into the opening of the bag, after which the clamping means grasps the adapter to provide a seal.
There is a need for a filling device which allows efficient and rational filling of collapsible type containers.